1. Field of the Invention
The present invention relates to dielectric information apparatus such as a recording apparatus for recording information in a small area of a dielectric substance, a reproducing apparatus for reproducing information recorded in a small area of a dielectric substance, and a recording/reproducing apparatus for recording information in and reproducing it from a small area of a dielectric substance.
2. Description of the Related Art
In recent years, many kinds of ferroelectric materials and piezoelectric materials have been developed and used for a supersonic, an optical device and a memory and the like. In association with it, a development of methods of measuring a residual polarization distribution of the ferroelectric material and a local anisotropy of the piezoelectric material has been advanced. With regard to the development in this field, the inventors of this application have developed a scanning nonlinear dielectric microscopy (SNDM) as a technique for a purely electrical detection of a polarization distribution of a material and a local anisotropy without any disturbance of a shield effect caused by free charges disposed on a surface.
The SNDM is the technique for detecting the condition of the polarization and the local anisotropy from a distribution measurement of a nonlinear dielectric constant of a material. As the technique of the SNDM, the development has been successively advanced such as a distribution constant type probe using a coaxial resonator and a small concentrated constant type probe using an LC resonator. The resolution of detection reaches a nano-meter order and further reaches a sub-nano-meter order. Moreover, quantitative measurement of linear/non-linear dielectric constant distributions has been able to be realized.
In this way, according to the SNDM, nondestructive measurement can be performed on the polarization distribution of a dielectric substance in an extremely small area. On the other hand, according to the SNDM, the polarization can be controlled by applying a predetermined electric field. Thus, the SNDM is an advantageous technique to attain the super high density dielectric recording/reproducing operation.
In order to attain the super high density dielectric recording/reproducing operation, SNDM is developed which is further small and suitable for the usage as the recording/reproducing apparatus. In this SNDM, a first electrode is formed on the rear surface of a dielectric record medium side, a second electrode serving as a probe is formed so as to be brought into contact with the small area of the dielectric substance (or brought into contact through small gap), and the plus or minus of a polarization of a small area recorded on a medium is read out by applying a low frequency alternating electric field for measurement between the first electrode and the second electrode from the first electrode. At this time, the second electrode is configured to be connected to a ground.
On the other hand, in order to attain the operation for recording/reproducing information at a high speed by using the SNDM, it is effective to use a plurality of probes and carry out the recording or reproducing by using them at the same time. However, in the conventional configuration, a plurality of resonators are required correspondingly to the number of the probes. As each resonator is relatively large in size, It is difficult to miniaturize the apparatus while integrating the plurality of large resonators. This is the factor that causes the miniaturization of the apparatus to be disturbed.